Conventionally, door-opening/closing devices for use in a vehicle have been proposed in, for example, Patent Document 1. According to such a device, a vehicle slide door 81 is supported to be movable in the fore-and-aft direction of a vehicle body 82 as shown in FIG. 8. The slide door 81 moves in the fore-and-aft direction by driving force of a driving member 83 provided on the vehicle body 82 or manual operating force to open and close a door opening 82a formed on the side portion of the vehicle body 82. That is, the slide door 81 moves in a range from a fully closed position, at which the door opening 82a is closed, to a fully open position, at which the door opening 82a is fully opened.
The driving member 83 includes a reversible motor 84 and a drum 85, which is rotationally driven by the motor 84.
A power transmission cable 86, the ends of which are connected to the slide door 81, is wound around the drum 85. The driving member 83 drives the slide door 81 by winding and unwinding the cable 86 through rotation of the motor 84 in accordance with the rotation direction of the motor 84.
An electromagnetic clutch is provided in a power transmission path between the motor 84 and the drum 85 and selectively enables and disables the power transmission path. The electromagnetic clutch is switched to a connected state when the slide door 81 is electrically opened or closed to transmit rotation of the motor 84 to the drum 85. The electromagnetic clutch is switched to a disabled state when the slide door 81 is manually opened or closed, and prevents rotation of the drum 85 from being transmitted to the motor 84. This is to allow the slide door 81 to be opened or closed with small operating force by separating rotation torque of the drum 85 from the motor 84 when, in particular, the slide door 81 is opened or closed manually.
A full-close lock 91, which retains the slide door 81 at the fully closed position by engaging with the vehicle body 82, and a full-open lock 92, which retains the slide door 81 at the fully open position by also engaging with the vehicle body 82, are provided on the slide door 81. The full-open lock 92 is disengaged from the vehicle body 82 upon reception of manual operating force from a manipulation lever 93 or electrical operating force from a release actuator 94, and allows the slide door 81 to be closed.